1 files changed, 327 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
new file mode 100644
index 000000000000..ce0b10fe5e2b
--- /dev/null
+++ b/arch/x86/kvm/svm/pmu.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KVM PMU support for AMD
+ *
+ * Copyright 2015, Red Hat, Inc. and/or its affiliates.
+ *
+ * Author:
+ *   Wei Huang <wei@redhat.com>
+ *
+ * Implementation is based on pmu_intel.c file
+ */
+#include <linux/types.h>
+#include <linux/kvm_host.h>
+#include <linux/perf_event.h>
+#include "x86.h"
+#include "cpuid.h"
+#include "lapic.h"
+#include "pmu.h"
+
+enum pmu_type {
+	PMU_TYPE_COUNTER = 0,
+	PMU_TYPE_EVNTSEL,
+};
+
+enum index {
+	INDEX_ZERO = 0,
+	INDEX_ONE,
+	INDEX_TWO,
+	INDEX_THREE,
+	INDEX_FOUR,
+	INDEX_FIVE,
+	INDEX_ERROR,
+};
+
+/* duplicated from amd_perfmon_event_map, K7 and above should work. */
+static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
+	[0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES },
+	[1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
+	[2] = { 0x7d, 0x07, PERF_COUNT_HW_CACHE_REFERENCES },
+	[3] = { 0x7e, 0x07, PERF_COUNT_HW_CACHE_MISSES },
+	[4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
+	[5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
+	[6] = { 0xd0, 0x00, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND },
+	[7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
+};
+
+static unsigned int get_msr_base(struct kvm_pmu *pmu, enum pmu_type type)
+{
+	struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
+
+	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
+		if (type == PMU_TYPE_COUNTER)
+			return MSR_F15H_PERF_CTR;
+		else
+			return MSR_F15H_PERF_CTL;
+	} else {
+		if (type == PMU_TYPE_COUNTER)
+			return MSR_K7_PERFCTR0;
+		else
+			return MSR_K7_EVNTSEL0;
+	}
+}
+
+static enum index msr_to_index(u32 msr)
+{
+	switch (msr) {
+	case MSR_F15H_PERF_CTL0:
+	case MSR_F15H_PERF_CTR0:
+	case MSR_K7_EVNTSEL0:
+	case MSR_K7_PERFCTR0:
+		return INDEX_ZERO;
+	case MSR_F15H_PERF_CTL1:
+	case MSR_F15H_PERF_CTR1:
+	case MSR_K7_EVNTSEL1:
+	case MSR_K7_PERFCTR1:
+		return INDEX_ONE;
+	case MSR_F15H_PERF_CTL2:
+	case MSR_F15H_PERF_CTR2:
+	case MSR_K7_EVNTSEL2:
+	case MSR_K7_PERFCTR2:
+		return INDEX_TWO;
+	case MSR_F15H_PERF_CTL3:
+	case MSR_F15H_PERF_CTR3:
+	case MSR_K7_EVNTSEL3:
+	case MSR_K7_PERFCTR3:
+		return INDEX_THREE;
+	case MSR_F15H_PERF_CTL4:
+	case MSR_F15H_PERF_CTR4:
+		return INDEX_FOUR;
+	case MSR_F15H_PERF_CTL5:
+	case MSR_F15H_PERF_CTR5:
+		return INDEX_FIVE;
+	default:
+		return INDEX_ERROR;
+	}
+}
+
+static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
+					     enum pmu_type type)
+{
+	switch (msr) {
+	case MSR_F15H_PERF_CTL0:
+	case MSR_F15H_PERF_CTL1:
+	case MSR_F15H_PERF_CTL2:
+	case MSR_F15H_PERF_CTL3:
+	case MSR_F15H_PERF_CTL4:
+	case MSR_F15H_PERF_CTL5:
+	case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
+		if (type != PMU_TYPE_EVNTSEL)
+			return NULL;
+		break;
+	case MSR_F15H_PERF_CTR0:
+	case MSR_F15H_PERF_CTR1:
+	case MSR_F15H_PERF_CTR2:
+	case MSR_F15H_PERF_CTR3:
+	case MSR_F15H_PERF_CTR4:
+	case MSR_F15H_PERF_CTR5:
+	case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
+		if (type != PMU_TYPE_COUNTER)
+			return NULL;
+		break;
+	default:
+		return NULL;
+	}
+
+	return &pmu->gp_counters[msr_to_index(msr)];
+}
+
+static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
+				    u8 event_select,
+				    u8 unit_mask)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++)
+		if (amd_event_mapping[i].eventsel == event_select
+		    && amd_event_mapping[i].unit_mask == unit_mask)
+			break;
+
+	if (i == ARRAY_SIZE(amd_event_mapping))
+		return PERF_COUNT_HW_MAX;
+
+	return amd_event_mapping[i].event_type;
+}
+
+/* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */
+static unsigned amd_find_fixed_event(int idx)
+{
+	return PERF_COUNT_HW_MAX;
+}
+
+/* check if a PMC is enabled by comparing it against global_ctrl bits. Because
+ * AMD CPU doesn't have global_ctrl MSR, all PMCs are enabled (return TRUE).
+ */
+static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
+{
+	return true;
+}
+
+static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
+{
+	unsigned int base = get_msr_base(pmu, PMU_TYPE_COUNTER);
+	struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
+
+	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
+		/*
+		 * The idx is contiguous. The MSRs are not. The counter MSRs
+		 * are interleaved with the event select MSRs.
+		 */
+		pmc_idx *= 2;
+	}
+
+	return get_gp_pmc_amd(pmu, base + pmc_idx, PMU_TYPE_COUNTER);
+}
+
+/* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
+static int amd_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+
+	idx &= ~(3u << 30);
+
+	return (idx >= pmu->nr_arch_gp_counters);
+}
+
+/* idx is the ECX register of RDPMC instruction */
+static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
+	unsigned int idx, u64 *mask)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	struct kvm_pmc *counters;
+
+	idx &= ~(3u << 30);
+	if (idx >= pmu->nr_arch_gp_counters)
+		return NULL;
+	counters = pmu->gp_counters;
+
+	return &counters[idx];
+}
+
+static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
+{
+	/* All MSRs refer to exactly one PMC, so msr_idx_to_pmc is enough.  */
+	return false;
+}
+
+static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	struct kvm_pmc *pmc;
+
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
+	pmc = pmc ? pmc : get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
+
+	return pmc;
+}
+
+static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	struct kvm_pmc *pmc;
+
+	/* MSR_PERFCTRn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
+	if (pmc) {
+		*data = pmc_read_counter(pmc);
+		return 0;
+	}
+	/* MSR_EVNTSELn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
+	if (pmc) {
+		*data = pmc->eventsel;
+		return 0;
+	}
+
+	return 1;
+}
+
+static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	struct kvm_pmc *pmc;
+	u32 msr = msr_info->index;
+	u64 data = msr_info->data;
+
+	/* MSR_PERFCTRn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
+	if (pmc) {
+		pmc->counter += data - pmc_read_counter(pmc);
+		return 0;
+	}
+	/* MSR_EVNTSELn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
+	if (pmc) {
+		if (data == pmc->eventsel)
+			return 0;
+		if (!(data & pmu->reserved_bits)) {
+			reprogram_gp_counter(pmc, data);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+
+	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
+		pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS_CORE;
+	else
+		pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
+
+	pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
+	pmu->reserved_bits = 0xffffffff00200000ull;
+	pmu->version = 1;
+	/* not applicable to AMD; but clean them to prevent any fall out */
+	pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
+	pmu->nr_arch_fixed_counters = 0;
+	pmu->global_status = 0;
+	bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters);
+}
+
+static void amd_pmu_init(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	int i;
+
+	BUILD_BUG_ON(AMD64_NUM_COUNTERS_CORE > INTEL_PMC_MAX_GENERIC);
+
+	for (i = 0; i < AMD64_NUM_COUNTERS_CORE ; i++) {
+		pmu->gp_counters[i].type = KVM_PMC_GP;
+		pmu->gp_counters[i].vcpu = vcpu;
+		pmu->gp_counters[i].idx = i;
+		pmu->gp_counters[i].current_config = 0;
+	}
+}
+
+static void amd_pmu_reset(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	int i;
+
+	for (i = 0; i < AMD64_NUM_COUNTERS_CORE; i++) {
+		struct kvm_pmc *pmc = &pmu->gp_counters[i];
+
+		pmc_stop_counter(pmc);
+		pmc->counter = pmc->eventsel = 0;
+	}
+}
+
+struct kvm_pmu_ops amd_pmu_ops = {
+	.find_arch_event = amd_find_arch_event,
+	.find_fixed_event = amd_find_fixed_event,
+	.pmc_is_enabled = amd_pmc_is_enabled,
+	.pmc_idx_to_pmc = amd_pmc_idx_to_pmc,
+	.rdpmc_ecx_to_pmc = amd_rdpmc_ecx_to_pmc,
+	.msr_idx_to_pmc = amd_msr_idx_to_pmc,
+	.is_valid_rdpmc_ecx = amd_is_valid_rdpmc_ecx,
+	.is_valid_msr = amd_is_valid_msr,
+	.get_msr = amd_pmu_get_msr,
+	.set_msr = amd_pmu_set_msr,
+	.refresh = amd_pmu_refresh,
+	.init = amd_pmu_init,
+	.reset = amd_pmu_reset,
+};